The proposed study is designed to characterize some of the occupational hazards that confront both pregnant and non-pregnant females engaged in occupations in which pesticide exposure is a distinct possibility. This investigation will explore the effect of pesticide exposure on embryonic gonadal development and on basic reproductive processes of the sexually mature female. Pesticides to be employed in this study are DDT, Diazinon, Malathion and Carbaryl. In the first part of this study, both chick and mouse embryos will be exposed to a single pesticide during the period of gonadal development. Effects of the pesticides on normal embryological development of the gonads and on sex differentiation will then be evaluated. This will involve tabulating the number of primordial germ cells (PGCs) colonizing the gonads, determining the sex of the embryos and detecting histochemically any alteration in enzyme activity in both PGCs and other cellular components of the gonads. In addition, some of the female mice exposed prenatally to pesticides will be followed to reach sexual maturity in order to determine whether embryonic exposure to pesticides can cause deleterious effects on basic ovarian functions which remain undetected until the period of sexual maturity. Measurements of the ability of the ovaries of the offspring to elicit an ovulatory response to exogenous gonadotropins and of the capacity of the ovarian oocytes to undergo normal meiosis will be used to assess these physiological capacities. The second part of this study will examine these same physiological parameters in ovaries of mice exposed to pesticides when sexually mature. An additional histochemical study of specific enzymes in the different cellular components of the ovary will provide information on the metabolic activities affected. Enzymes to be assessed include acid and alkaline phosphatase, beta-glucuronidase, ATPase, and delta 5-3 Beta-hydroxysteroid dehydrogenase. Results obtained from an examination of the effects of pesticide exposure on the prenatal embryo and the sexually mature femals should provide for more critical evaluation of health and safety standards not only for pregnant women but also for women desiring future pregnancy.